Polishing machine



Jan. 22, 1929.

1,700,115 C. H. THOMPSON POLISHING MACHINE Filed Sept. 25, 1926 5 Sheets-Sheet 1 28 85 2.9 30 J1 //v VENTOR" 4/ wfh 4' ATTORNEY Jan. 22, 1929.

C. H. THOMPSON POLISHING MACHINE Filed Sept. 23, 1926 5 Sheets-Sheet 2 Jan. 22, 1929. 1,700,115

C. H. THOMPSON POLISHING MACHINE Filed Sept. 25. 1926 s Sheets-Sheet 5 ATTO ENE) Patented Jan. 22, 1929.

UNITED STATES PATENT OFFICE.

CLAUDE H. THOMPSON, OF BINGHAMTON, NEW YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CLAUDE H. THOMPSON, ANDS'I'OW MANUFACTURING COMPANY, OF IBINGHAMTON, NEW YORK, A CORPORATION OF NEW YORK.

POLISHING MACHINE.

Application filed September 23, 1926. Serial No. 137,241.

This invention relates to machines for polishing surfaces to give them a smooth finish, and more particularly to a machine for polishing either flat or curved surfaces.

Polishing machines provided with reciprocating pads have been proposed heretofore, and these proposed machines work satisfactorily when employed to polish tables, desks and other flat surfaces, but they are not adapted to polish curved surfaces. The work of polishing curved surfaces such as automobile bodies and parts of furniture, has therefore been performed heretofore by hand which is slow and expensive.

The present invention is therefore directed to a power operated machine which is adapted to polish either fiat or curved surfaces.

One important feature of the present invention resides in a polishing machine having a flexible pad that is connected to its operating means so that the pad may be flexed to conform to either concaved or convexed surfaces, and in the means for holdin the pad in conformity with the surface eing polished.

Another feature of the invention resides in the construction of the casing for the operating parts, whereby the mechanism for operating the pad of the polishing machine is completely housed to protect the operating parts from the dirt and dust produced by the polishing operation. 1

Another feature of the invention resides in the construction whereby different pads may be readily secured to and removed from the polishing machine to perform different polishing operations.

Still another feature of the invention resides in clamping means for securing sheets of abrasive material, such as sandpaper, to a' polishing pad.

Other features of the invent-ion and novel combination of parts in addition to the above will be hereinafter described in connection with the accompanying drawings which illustrate a good practical form of the invcntion.

In the drawings Fig. 1 is a perspective view of a polishing machine constructed in accordance with the present invention;

Fig. 2 is a bottom view of Fig. 1. the polishing pads and floor-plate being removed;

Fig. 3 is a longitudinal sectional view through the machme of Fig. 1, but shows the polishing pads formed of different material from that of Fig. 1-;

Fig. 4 is a central transverse sectional view Fig. 7 is a perspective view of a block-holdlng element;

polishing Fig. 8 is a perspective view of the pad of i Fig. 5;

Fig. 9' is an end view of pad actuating elements shown in spaced relation to each other;

Fig. 10 is a perspective view of a sliding shuttle for operating a pad; and

Fig. 11 is a face view of the portion of the block-holding element upon which the spring latch is mounted.

The polishing machine forming the subject matter of the present invention may be given any size found desirable, but in the construction shown the size of this machine is such that it may be readily handled by one hand of the operator, as indicated in Fig. 1 of the drawing, while at the same time the operator may hold the flexible pads in conformity with the surface being polished by exerting pressure upon different portions of the hand grip, as will be hereinafter more fully pointed out.

The mechanism for imparting polishing movements to the pad or pads is preferably enclosed in a tight casing so that the operating parts are protected from the dirt and dust incident to the polishing operation. The features of the present invention may be employed in connection with a single polishing pad, but in most cases it is desirable to provide a pair of polishing pads which are moved toward and from each other-during their polishing operation, as a pair of operating pads will cause the casin to vibrate less than when a single pad is empibyed.

The casing 10 in which the operating mechanism is enclosed may be formed of any suitable metal, and since it is desirable to reduce the weight of the polishing machine as far as practical, the casing may well be formed of aluminum. This casing is provided with the opposite side walls 11 and the end walls 12, and a rib or raised portion 13 is formed transversely across the upper portion of the casing. The casing so far described may constitute an integral structure having the form of a hollow box the bottom of which is 0 en and this opening may be closed with a oor plate 14 which preferably has its side edges beveled to fit snugly in the correspondingly shaped grooves 15 formed in the opposite walls 11 of the box, the arrangement being such that the floor plate may be slid along the grooves 15 into and out of the closed position. The box construction just described constitutes a greasetight receptacle in which grease may be confined about the operating mechanism within the box. The floor plate may be secured in its closed position by bending a portion 16 thereof upwardly and by securing this portion to an end wall 12 of the box by a screw 17.

In the construction shown the polishing machine is provided with a pair of flexible polishing pads 18 which are moved towards and from each other with a reciprocatory movement and each pad 18 has a marginal portion secured to its operating means while the remaining portion of the pad projects from the reciprocating means so that the pad may be flexed either downwardly as shown in Fig. 1, or upwardly as indicated in dotted lines in Fig. 3. As a result the polishing pads are adapted to conform either to a concave or a convex surface being polished.

It is desirable to provide manually controlled means for holding the flexible pads against the work in conformity with the curved or flat surface being polished, and this is accomplished, in accordance with the present invention, by providing a flexible hand grip 19 which may be formed of thick leather, or other flexible material, and the central portion of which is secured to the rib 13 of the casing by the screws 20, and the stiifness and strength of the sheet 19 may be increased by securing a thin sheet of flexible metal 21 to its under face by rivets 22. The rib 13 serves to hold the hand grip 19 in spaced relation to the upper face of the easing so that the end portions of the hand grip may be bent downwardly a substantial amount without engaging the upper face of the casing. The pressure exerted by the hand of the operator upon the hand rest. 19 to flex the pads 18 is transmitted to these pads by depressors attached to the opposite ends of the hand rest, and which may be formed of the vertically disposed legs 23 which preferably are secured to the flexible pad 18 by a hinge connection. The legs 23 are shown as bent at their upper end,but the need of bending these legs may be avoided by increasing the length of the flexible pad 18. The upper end of each leg 23 is secured by a hinge pin 24 to a hinge plate 25 which is secured by rivets 26 to the under face of the hand rest near a corner thereof. The pair of legs 23 provided at an end of the hand rest are preferably connected by a transversely extending bar 27 that may be riveted or otherwise secured to the legs 23. Each leg 23 is provided at its lower end with a roller 28 and the legs 23 are held in spaced relation to the {ends of the casing 10 by the links 29. These links are shown as having their outer ends bent at right angles to the major portion of the link and this bent end is inserted in a drill hole formed transversely through the leg 23. -The opposite end of each link is bent to form a loop 30 and the looped portion of each link is secured to a side wall 11 of the casing by a screw 31, two links being secured to a side wall 11 by a single screw. As a result of the link construction just described, the depressor legs 23 are held in approximately parallel relation to the ends of the casing 10 throughout their entire range of movement.

It will be understood that the pads 18 are reciprocated with respect to the depressor legs 23, and if the rollers 28 were permitted to directly engage the reciprocating pads 18 they might injure the upper-face of the pads. To prevent this each ad 18 is preferably provided with a flexible backing plate 32 formed of sheet metal. As a result of this construction the rollers 28 which are forced toward the pads to flex them roll smoothly upon the backing plates 32, while the pads partake of their reciprocatory movement.

The driving mechanism for imparting the reciprocatory movement to the pads 18 might be variously constructed, and one good practical construction to this end which is strong and durable is shown in the drawings and will now be described. lVithin the hollow casing 10 are mounted a pair of sliding elements or shuttles 33. These shuttles are supported within the casing for sliding movement by the longitudinally extending bars 34 which extend through holes 33 formed in the shuttles 33. One end of each bar 34 has a reduced end 35 that extends into a hole formed in an end wall 12 of the casing, and the other end of each of these bars is mounted in a hole 36 construction ust described the shuttles 33 are. slidably supported inspaccd relation to th side walls 11 of the casing.

In order to impart reciprocatory movement to the shuttles 33 a driving pinion 37 is supported within the casing 10 adjacent the upper wall of the casing and this pinion is rigidly secured to the driving shaft 38 which is j ournaled in a hollow externally threaded lug that projects upwardly from the rib 13. The upper portion of the shaft 38 is larger in diameter than the lower end portion thereof so that the shoulder 40 is formed, and this shoulder rests upon the anti-friction bearing 41. It should be noted that the driving shaft 38 is disposed near one end of the. transversely extending rib 13. This is desirable to better accommodate the hand of the operator as will be apparent from Fig. 1, wherein the operators hand is indicated in dotted lines, and also to position the pinion 37 at one side of the axes of the gears 42 which mesh with and are driven by the pinion 37. Each gear 42 is rotatably mounted on a fixed stub shaft 43 the upper end of which is rigidly secured in a boss 44 formed upon the upper face of the casing, and the gears 42 are held in the operative position upon the stub shafts by the shuttles 33 which they operate. The arrangement is such that when it is desired to disassemble the driving mechanism of the polishing machine the shuttle supporting bars 34 may be removed from the casing, whereupon the shutttles 33 may be removed and the gears 42 may be stripped from their stub shafts. In order to cause the gears 42 to reciprocate the shuttles 33 each gear has a pin 45 that projects downwardly from its lower face at one side of its central axis and upon each pin 45 is mounted a ring 46 which is received in the space provided between the upstanding lugs 47 formed at the upper face of each shuttle 33, as best shown in Fig. 10. In order to reduce the friction between the pins 45 and rings 46 the rings are preferably provided with the anti-friction bearings 48, as will be apparent from Fig. 2.

The means for imparting the reciprocatory movement of the shuttles 33 to the flexible pads 18 should be so constructed that dirt and dust and the liquid which may be used in the polishing operation will be prevented from finding its way into the interior of the casing 10. and to this end each shuttle 33 is provided with a block-holder 49 which is disposed adjacent the outer face of the floor plate 14. Each block holder 49 is secured to its shuttle in spaced relation thereto by a transversely 1 extending rib 50 that projects from its upper face and is snugly received in a. groove 51 formed in the lower face of the shuttle, as best shown in Fig. 9, the block-holder being secured to the shuttle by the screws 52. The rib 50 extends through a hole 53 formed in the floor plate 14, which hole issutliciently wide to permit the parts just mentioned to partake of their reciprocatory movement, and it should be noted that the block-holder 49 is provided with the relatively wide flange portions 54 which serve to completely cover the opening 53 of the floor plate throughout the reciprocatory movement of the shuttle. In this manner dirt, dust and moisture are prevented from entering the interior of the casing 10' through the openings 53.

It is frequently desirable to change the polishing pads used upon the polishing machine in order to substitute a new pad for an old one, or to perform different polishing operations. For example, in some cases it may be desirable to employ the felt pads 18 shown in Figs. 1 and 4, while in other cases it may be desirable to employ the rubber pads 55 shown in the other figures of the drawings. One desirable feature of the present invention, therefore, resides in simple means for removably securing the pads to the blockholders 49 so that the pads may be readily secured to and moved from the block-holders. This is accomplished in the construct-ion shown by providing each pad 18 and 55 with a block 56 that is firmly secured to the upper face of the pad near one end thereof by screws which extend downwardly through holes in the block 56 and have threaded engagement with nuts embedded in the interior of the pads (see 3), the backing plates 32 being confined between the upper face of the pads and the blocks 56. The blocks 56 and the block-holders 49 are preferably provided with the interengaging dove-tailed portions best shown in Figs. 7, 8 and 9, wherein it will be seen that each block 56 has the dove-tailed slot 57 adapted to receive the correspondingly shaped dovetailed portion 58 of the block-holder 49, the arrangement being such that the block 56 may be secured to and removed from its block-holder 49 by movement of the block transversely of the polishing machine. The dove-tailed portion 58 is slid within the slot 57 until the notched portion 59 thereof strikes the pin stop 60, and the parts are held in their assembledrelation by the spring operated latch 61 that is secured to the under face of the block-holder 49 by the pivot pin 62, the arrangement being such that when the parts are assembled the lip 63 of the latch engages an end of the block 56, as best shown in Fig.

In performing some polishing operations it may be desirable to secure abrasive material such as sandpaper to the active face of each polishing pad, and means is therefore provided, in accordance with the present invention, for readily attaching the sheets 55 of abrasive material to each pad. Such means consists ofthe. clamping plates 65 which are disposed at the inner end of each of the pads 55. Each clamping plate 65 is pivotally secured at its upper end by a pivot pin 66 t0 the block 56, and the lower end of each clamp 65 is constructed to clamp the abrasive material between its inner face and a backing plate 67 that is confined between the inner face of the pad 55 and the plate 32,

the backing plate being provided with the downwardly extending lip portion' 67 that engages the abrasive material. These clamps are held in the clamping position by t 1e U-shaped elements 68 which extend transversely through the blocks 56 and have their ends secured to a bridge bar 68, the parts being forced to the clamping position by tightenlng the screw 68.

In order to secure the opposite ends of the sheets of abrasive material to a pad, the clamping plates 69 and 70 are provided, and these two plates are clamped to the opposite faces of an abrasive sheet by tightening the thumb screw 71. The clamp thus formed is held in place upon the backing plate 32 of a ad by a coiled spring 72 one end of which is secured to the clamp 69 as at 73, while the opposite end of the spring is provided with a hooked portion which may be engaged in a hole 7 formed in the hacking plate 32. As a result of the construction just described, the clamping means provided with the spring 72 is fioatingly held at the back of a pad and the spring serves to maintain a constant tension upon the sheet of abrasive material. This floating arrangement is desirable because it prevents the clamping elements 69 and 70 from interfering with the flexing of the polishing pad upon which it rests.

Power for operating the driving mechanism described is preferably imparted to the stub shaft 38 by a flexible shaft 7 5 which may lead from a motor or other source of power located some distance from the polishing machine, and one end of the protecting casing for the flexible shaft may be attached to the polishing machine by the nut 76 which is" screwed into the upper end of the internally threaded sleeve 77 that is rigidly secured to the upstanding post 39 above mentioned. The lower end of the sleeve 77 may engage a washer 78 provided upon the upstanding post 39 to help retain the hand rest 19 in place. i

The sleeve 77 is preferably provided with a laterally extending lug portion 79 positioned to extend over the thumb of the operator and an oppositely extending firiger-like portion 80 extends over the back of the hand of the operator, and the lower face of the portion 80 is padded as at 81. This pad 81, which engages the hack of the operators hand, gives him better control over the polishing machine and acts as a brace for the hand when the hand is arched to force downwardly the end portions of the hand grip 19.

If the flexible cable is driven by an electric motor it may be desirable to provide the polishing machine with means for starting and stopping the motor. -'This may be done by providing the hand operated switch 82 which is connected to the conductor wires 83 leading to the electric motor. An oil hole 84 is provided to lubricate the bearing 41, and

grease for lubricating the operating parts withln the casing 11 may be supplied to the cas ng through an opening in a side wall 11, \8V5h1Cll opening is closed by the threaded plug From the foregoing description and drawings it will be seen that the polishing machine forming the subject matter of the present invention may readily be moved over the surface being polished by one hand and that the pads may be flexed as shown in Fig. 1 by merely exerting a downward pressure upon the end portions of the hand grip 19.

What is claimed is z-- 1. In a surface polishing machine, the combination of a flexible polishing element, means for supporting the flexible element at one part thereof with permissive bending of the remaining portion of the element to conform to the curvature of the surface being polished, means for imparting a non-rotative polishing movement to the element, a depressor positioned to act upon said remain ing portion of the flexible element independently of said supporting means to increase the pressure thereon without increasing the pressure upon the element supporting means to thereby bend the element in conformity with the surface being polished, and a flexible protecting plate interposed between said element and the depressor to prevent the latter from coming in direct contact with said element.

2. In a surface polishing machine, the combination of a flexible polishing element, means for supporting the flexible element at one part thereof with permissive bending of the remaining portion of the element to conform to the curvature of the surface being polished, means for imparting a non-rotative polishing movement to the element, a depressor having a roller positioned to act upon a different portion of the flexible element from that to which said supporting means is secured to increase the pressure thereupon without increasing the pressure on the supporting means and operable to bend said element in conformity with the surface being polished, and a flexible protecting plate interposed between said element and roller and having a hard smooth surface against which the roller acts.

3. A surface polishing machine, compris ing in combination, a casing, means supported by the casing to impart polishing movement to a pad, a flexible pad connected to said means to be operated thereby and having a portion projecting from the means so that the pad may be flexed in conformity with .the surface to be polished, a pad depressor supported to act upon a different portion of the pad from that to which said supported means is connected and adapted to increase the pressure upon the projecting portion of the pad without increasing the pressure upon the portion of the pad connected to said means to thereby bend the pad to conform to said surface, and a flexible backing plate for the pad against which the depressor acts in flexing the pad.

4. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart reciprocatory movement to a polishing pad, a pad connected to said means to be operated thereby and having a portion projecting from the means so that the pad may be flexed in conformity to the surface being polished, a pad depressor supported to act upon the pad without partaking of its polishing movement and adapt ed to hold the pad against said surface, and a backing plate secured to the pad and against which the depressor acts in flexing the pad.

5. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart polishing movement to a pad, a flexible pad connected to said means to be operated thereby and having a portion projecting from the means so that the pad may be flexed in conformity with the surface being polished, a pad depressor supported to act upon a different portion of the pad from that to which said supported means is connected and operable to increase the pressure upon the projecting portion of the pad without increasing thepressure upon the portion of the pad to which said means is connected and operable to bend the pad in conformity with the surface being polished, and a link connection between the depressor and casing for movably supporting the depressor.

6. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart polishing movement to a pad, a flexible pad connected to said means to be reciprocated thereby and having a portion projecting from the means so that the pad may be flexed in conformity with the surface being polished, a pad depressor supported to act upon a different portion of the pad from that to which said supported means is connected and operable to increase the pressure upon the projecting portion of the pad without increasing the pressure upon the portion of the pad to which said means is connected and operable to bend the pad in conformity with the surface being polished, and means for holding the depressor in spaced relation to the casing throughout its pad flexing, movements.

7. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart polishing movement to a pad, a flexible pad connected to said means to beoperated thereby and having a portion projecting from the means so that the pad may be flexed in conformity with the surface being polished, a pad depressor adapted to act upon a different portion of I pressure of said means to the projecting the pad from that to which said means is connected and operable to increase the pressure upon the pro ecting portion of the pad without increasing thepressure upon the portion of the pad to which said means is connected and operable to bend the pad in conformity with the surface being polished, and hinged means for connecting the depressor to said casing. 8. A surface polishing machine, comprismg in combination, a casing, means associated with the casing for imparting polishing movement to a be operated by said means and having a portion extending from the means so that the pad may be flexed in conformity with the surface being polished, a pad depressor adapted to act upon the pad to hold it in conformity with the surface being polished, an element for connecting the depressor to said casing and adapted to be manually engaged to actuate the depressor, and a hinge connection between the depressor and said element.

9. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart polishing movement to a pad, a flexible pad connected to said means to be operated thereby and having a portion projecting from the means so that the pad may be flexed to conform to the surface being polished, means supported above the casing and manually movable to force the pad against the surface being polished, and a pad depressor hinged to said manually movable means and adapted to transmit the tion of the pad. I

10. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart reciprocatory movement to a pad, a flexible pad connected to said means to be reciprocated thereby and having a portion projecting from the means so that the pad may be flexed to conform to the surface being polished, a pad depressor for forcing the projecting portion of the pad against the surface being polished, and links secured to said depressor to hold it approximately parallel to the casing.

11. A surface polishing machine, comprising in combination, a casing, means supported by the casing to impart polishing movementto a pad, a flexible pad connected to said means to be reciprocated thereby and having a portion projecting from the means so that pad, a flexible pad adapted to the pad may be flexed to conform to the suring in combination, a casing, a pair of flexible pads, means supported by the casing for 1mparting reciprocatory movements to the pads and connected to the pads so that they may be flexed to conform to the surface being polished, means attached to the casing and manually movable to force the pads against the surface being polished, pad depressors for transmitting the movement of the manually movable means to the pads, and a link connection between each depressor and the easing for holding the depressors in spaced relation to the casing.

13. A surface polishing machine, comprising in combination, a casing, a pair of flex ble pads, means supported by the casing for 1mparting reciprocatory movement to the pads and connected to the pads so that they may be flexed to conform to the surfacebeing polished, a flexible hand rest secured to the easing and adapted to be manually flexed to force the pads against the surface being polished, a bar supported in spaced relation to the casing to engage the back of the operators hand, pad depressors for transmitting the pressure upon the manually movable means to the pads, and links for holding the depressors in spaced relation to the casing.

14. A surface polishing machine, comprising in combination, a hollow casing, a floor plate for tightly closing the casing and having its side edges'fitted in grooves formed at the opposite sides of'the casing so-that the floor plate may be slid to and from its closed position, a pad actuator slidably mounted within the casing, a rod mounted in the easing to slidably support said pad actuator and having an end extending through a wall of the casing, a flexible pad adapted to be reciprocated by the actuator, means extending through a hole in the floor plate to impart the movement of the actuator to the pad, a projection upon said floor plate formed to extend over the end of said rod to hold the rod in place, and means acting upon a projecting portion of the pad to flex it into conformity with the surface being polished.

15. A surface polishing machine, comprising in combination, a hollow casing, a floor plate for tightly closing the casing to form a grease-tight receptacle, a pad actuator slid ably mounted within the casing, a flexible pad adapted to be reciprocated by the actuator, means extending through a hole in the floor plate to impart the movement of the actuator to the pad, a depressor adapted to act upon a projecting portion of the pad to flex it in conformity with the surface being polished, and link means for holding the depressor in spaced relation to the casing.

16. A surface polishing machine comprising in combination, a casing, a a actuator supported by the casing, a flexi 1e pad connected to the pad actuator to be operated thereby and having a portion projecting therefrom so that the pad may be flexed in conformity with the surface being polished, means for operating the actuator to impart a nonrotative polishing movement to the pad, and means for securing a sheet of abrasive material across a face of the pad, including sheet engaging means for holding one end of the abrasive sheet, a 1pair of clampin jaws between which the ot er end of the sheet is gripped, and flexible means for connecting the pair of clamping jaws to the pad for flogting movement relative to the flexible p 17. A surface polishing machine, comprising in combination, a casing, a pad actuator supported by the casing, a flexible pad connected to the pad actuator to be operated thereby and having a ortion projecting therefrom so that the pad may be flexed in conformity with the surface being polished, means for operating the actuator to lmpart a nonrotative polishing movement to the pad, and means for securing a sheet of abrasive material across a face of the pad, including sheet engaging means for holding one end of the abrasive sheet, a pair of clamping jaws between which the other end of the sheet is gripped, and a spring .for connecting the pair of clamping jaws to the pad for floating movement relative to the flexible pad and adapted to exert a continuous tensioning pull upon the sheet. a

18. A surface polishing machine, comprising in combination, a casing, a pad actuator supported by the casing, a flexible pad connected to the pad actuator to be operated thereby and having a portion that may be freely flexed, means for operating the actuator to impart a polishing movement to the pad, and means for securing a. sheet of abrasive material across a face of the pad, including sheet engaging means for holding one end of the abrasive sheet, a bar ada ted to be attached to the other end of sai sheet, and means for holding the bar against the pad with a floating movement so that the bar will not interfere with the flexing of the pad.

In testimony whereof, I have signed my name to this specification.

CLAUDE H. THOMPSON. 

